We have determined the masses and mass-to-light ratios of 50 Galactic globular clusters by comparing their velocity dispersion and surface brightness profiles against a large grid of 900 N-body simulations of star clusters of varying initial concentration, size and central black hole mass fraction. Our models follow the evolution of the clusters under the combined effects of stellar evolution and two-body relaxation allowing us to take the effects of mass segregation and energy equipartition between stars self-consistently into account. Our results show that the mass-to-light ratios of Galactic globular clusters agree well with the expected M/L ratios for standard Kroupa or Chabrier mass functions. Contrary to recent literature claims we do not find a decrease of the average mass-to-light ratio with metallicity. The surface brightness and velocity dispersion profiles of most globular clusters are incompatible with the presence of intermediate-mass black holes in them. The only exception is Omega Cen, where the velocity dispersion profile provides strong evidence for the presence of a 40,000 Msun IMBH in the centre of the cluster.